Piceid Octanoate Protects Retinal Cells against Oxidative Damage by Regulating the Sirtuin 1/Poly-ADP-Ribose Polymerase 1 Axis In Vitro and in rd10 Mice.

Retinitis pigmentosa is a common cause of inherited blindness in adults, which in many cases is associated with an increase in the formation of reactive oxygen species (ROS) that induces DNA damage, triggering Poly-ADP-Ribose Polymerase 1 (PARP1) activation and leading to parthanatos-mediated cell death. Previous studies have shown that resveratrol (RSV) is a promising molecule that can mitigate PARP1 overactivity, but its low bioavailability is a limitation for medical use. This study examined the impact of a synthesized new acylated RSV prodrug, piceid octanoate (PIC-OCT), in the 661W cell line against H2O2 oxidative stress and in rd10 mice. PIC-OCT possesses a better ADME profile than RSV. In response to H2O2, 661W cells pretreated with PIC-OCT preserved cell viability in more than 38% of cells by significantly promoting SIRT1 nuclear translocation, preserving NAD+/NADH ratio, and suppressing intracellular ROS formation. These effects result from expressing antioxidant genes, maintaining mitochondrial function, reducing PARP1 nuclear expression, and preventing AIF nuclear translocation. In rd10 mice, PIC-OCT inhibited PAR-polymer formation, increased SIRT1 expression, significantly reduced TUNEL-positive cells in the retinal outer nuclear layer, preserved ERGs, and enhanced light chamber activity (all p values < 0.05). Our findings corroborate that PIC-OCT protects photoreceptors by modulating the SIRT1/PARP1 axis in models of retinal degeneration.

Mesoporous Silica-Based Nanoparticles as Non-Viral Gene Delivery Platform for Treating Retinitis Pigmentosa.

BACKGROUND: Gene therapy is a therapeutic possibility for retinitis pigmentosa (RP), in which therapeutic transgenes are currently delivered to the retina by adeno-associated viral vectors (AAVs). Although their safety and efficacy have been demonstrated in both clinical and preclinical settings, AAVs present some technical handicaps, such as limited cargo capacity and possible immunogenicity in repetitive doses. The development of alternative, non-viral delivery platforms like nanoparticles is of great interest to extend the application of gene therapy for RP. METHODS: Amino-functionalized mesoporous silica-based nanoparticles (N-MSiNPs) were synthesized, physico-chemically characterized, and evaluated as gene delivery systems for human cells in vitro and for retinal cells in vivo. Transgene expression was evaluated by WB and immunofluorescence. The safety evaluation of mice subjected to subretinal injection was assessed by ophthalmological tests (electroretinogram, funduscopy, tomography, and optokinetic test). RESULTS: N-MSiNPs delivered transgenes to human cells in vitro and to retinal cells in vivo. No adverse effects were detected for the integrity of the retinal tissue or the visual function of treated eyes. N-MSiNPs were able to deliver a therapeutic transgene candidate for RP, PRPF31, both in vitro and in vivo. CONCLUSIONS: N-MSiNPs are safe for retinal delivery and thus a potential alternative to viral vectors.

The role of phase I and II genetic polymorphisms, smoking, alcohol and cancer family history, in the risk of developing testicular cancer.

BACKGROUND: Testicular cancer (TCa) is a malignant tumor with highest incidence and mortality rates in Chile. The genes coding for cytochrome P450, glutathione-S-transferases (GSTs), and UDP glucuronyl transferases (UGT) participate in the biotransformation and detoxification of xenobiotics. Mutations in these genes have been associated with a high incidence of various types of cancer and an increased risk of presenting adverse reactions to drugs. OBJECTIVE: The aim of this study was to relate the presence of genetic polymorphisms in cytochrome P450 1A1 (CYP1A1), CYP3A4, GSTM1, GSTP1, GSTT1, and UGT1A1 genes and nongenetic factors with the risk of developing TCa. METHODS: A total of 276 volunteers from the Chilean general population and 251 Chilean TCa patients were recruited for the study. Genotypic analyses were performed using qPCR and PCR-RFLP. RESULTS: Variant alleles found to increase the risk of developing TCa were CYP1A1*2C (rs1048943), GSTP1 (rs1695), and GSTT1null, especially when in conjunction with a cancer family history and/or a smoking habit. The results of the multivariate analysis showed that the presence of variant alleles of GSTP1 (rs1695) together with a smoking habit and a family history of cancer accounted for a 15.9% risk of developing TCa in the Chilean population. CYP1A1*2C, GSTM1null, GSTT1null, and GSTP1 (rs1695) are statistically related to the risk of appearance of TCa, alone or associated with nongenetic factors. CONCLUSION: Therefore, phase I and II variant alleles might be useful in evaluating susceptibility to TCa in the studied population.

Association Study Among Candidate Genetic Polymorphisms and Chemotherapy-Related Severe Toxicity in Testicular Cancer Patients.

Testicular cancer is one of the most commonly occurring malignant tumors in young men with fourfold higher rate of incidence and threefold higher mortality rates in Chile than the average global rates. Surgery is the initial line of treatment for testicular cancers, and is generally followed by chemotherapy, usually with combinations of bleomycin, etoposide, and cisplatin (BEP). However, the adverse effects of chemotherapy vary significantly among individuals; therefore, the present study explored the association of functionally significant allelic variations in genes related to the pharmacokinetics/pharmacodynamics of BEP and DNA repair enzymes with chemotherapy-induced toxicity in BEP-treated testicular cancer patients. We prospectively recruited 119 patients diagnosed with testicular cancer from 2010 to 2017. Genetic polymorphisms were analyzed using PCR and/or qPCR with TaqMan ®probes. Toxicity was evaluated based on the Common Terminology Criteria for Adverse Events, v4.03. After univariate analyses to define more relevant genetic variants (p < 0.2) and clinical conditions in relation to severe (III-IV) adverse drug reactions (ADRs), stepwise forward multivariate logistic regression analyses were performed. As expected, the main severe ADRs associated with the non-genetic variables were hematological (neutropenia and leukopenia). Univariate statistical analyses revealed that patients with ERCC2 rs13181 T/G and/or CYP3A4 rs2740574 A/G genotypes are more likely to develop alopecia; patients with ERCC2 rs238406 C/C genotype may develop leukopenia, and patients with GSTT1-null genotype could develop lymphocytopenia (III-IV). Patients with ERCC2 rs1799793 A/A were at risk of developing severe anemia. The BLMH rs1050565 G/G genotype was found to be associated with pain, and the GSTP1 G/G genotype was linked infection (p < 0.05). Multivariate analysis showed an association between specific ERCC1/2 genotypes and cumulative dose of BEP drugs with the appearance of severe leukopenia and/or febrile neutropenia. Grades III-IV vomiting, nausea, and alopecia could be partly explained by the presence of specific ERCC1/2, MDR1, GSTP1, and BLMH genotypes (p < 0.05). Hence, we provide evidence for the usefulness of pharmacogenetics as a tool for predicting severe ADRs in testicular cancer patients treated with BEP chemotherapy.

[Pharmacogenetics, tobacco, alcohol and its effect on the risk development cancer]. / Farmacogenética, tabaco, alcohol y su efecto sobre el riesgo de desarrollar cáncer.

Cancer is the second leading cause of death in the world, causing 8.8 million deaths in 2015 according to the World Health Organization (WHO). Risk factors for cancer include smoking and alcohol con sumption. In Chile, 33.6% of the population and 21.2% of young people smokes. Alcohol consump tion in the Chilean population is 74.5% and 12.2% in young people. Among the physiological factors that influence the development of cancer, the genetic factor plays a relevant role. It has been shown that the presence of genetic polymorphisms that alter the ability of the body to eliminate contami nants increase the risk of developing cancer. The same applies to polymorphisms that prevent DNA repair due to damage caused by environmental pollutants such as cigarette smoke. The objective of this review is to analyze the state of the art of the relationship between pharmacogenetics, smoking, and alcohol consumption as risk factors for the development of cancer. In conclusion, the results suggest that the presence of polymorphisms that alter the function of biotransformation enzymes phase I (CYP1A1, CYP1E1) and phase II (GST), as well as polymorphisms in DNA repair enzymes (ERCC1 / ERCC2), increase the risk of cancer induced by smoking and alcohol consumption. This association is important considering that smoking and drinking alcohol are highly prevalent among the Chilean population.

Farmacogenética, tabaco, alcohol y su efecto sobre el riesgo de desarrollar cáncer / Pharmacogenetics, tobacco, alcohol and its effect on the risk development cancer

El cáncer es la segunda causa de muerte en el mundo, según datos de la Organización Mundial de la Salud (OMS) en el año 2015 ocasionó 8,8 millones de muertes. Dentro de los factores de riesgo para el desarrollo de cáncer se encuentran el tabaquismo y el consumo de alcohol. En Chile el 33,6% de la población fuma y un 21,2 % de los jóvenes. El consumo de alcohol en la población chilena es de 74,5 % y en los jóvenes de un 12,2 %. Entre los factores fisiológicos que influyen en el desarrollo de cáncer, el factor genético juega un rol relevante, habiéndose demostrado que la presencia de polimorfismos genéticos alteran la capacidad del organismo de eliminar contaminantes y aumentan el riesgo de desarrollar cáncer. Lo mismo ocurre con polimorfismos que impiden la reparación de ADN debido a daños producidos por efecto de contaminantes ambientales como el humo de cigarrillo. El objetivo de esta revisión es analizar el estado del arte de la relación entre farmacogenética, tabaco y alcohol como factores de riesgo para el desarrollo de cáncer. Los resultados sugieren que la presencia de po limorfismos que alteran la función de enzimas de biotransformación fase I (CYP1A1, CYP1E1) y fase II (GST), además de polimorfismos en enzimas de reparación del ADN (ERCC1/ERCC2) aumentan el riesgo de cáncer inducido por el hábito tabáquico y alcohólico. Esta asociación es importante, si consideramos que en la población chilena el hábito de fumar y beber alcohol es altamente prevalente.

Cancer is the second leading cause of death in the world, causing 8.8 million deaths in 2015 according to the World Health Organization (WHO). Risk factors for cancer include smoking and alcohol con sumption. In Chile, 33.6% of the population and 21.2% of young people smokes. Alcohol consump tion in the Chilean population is 74.5% and 12.2% in young people. Among the physiological factors that influence the development of cancer, the genetic factor plays a relevant role. It has been shown that the presence of genetic polymorphisms that alter the ability of the body to eliminate contami nants increase the risk of developing cancer. The same applies to polymorphisms that prevent DNA repair due to damage caused by environmental pollutants such as cigarette smoke. The objective of this review is to analyze the state of the art of the relationship between pharmacogenetics, smoking, and alcohol consumption as risk factors for the development of cancer. In conclusion, the results suggest that the presence of polymorphisms that alter the function of biotransformation enzymes phase I (CYP1A1, CYP1E1) and phase II (GST), as well as polymorphisms in DNA repair enzymes (ERCC1 / ERCC2), increase the risk of cancer induced by smoking and alcohol consumption. This association is important considering that smoking and drinking alcohol are highly prevalent among the Chilean population.

Adjuvant chemoradiation for resected gallbladder cancer: Treatment strategies for one of the leading causes of cancer death in Chilean women.

BACKGROUND: Gallbladder cancer (GBC) is the second leading cause of cancer death in women in Chile. Even after curative surgery, prognosis is grim. To evaluate acute and late toxicity and efficacy of adjuvant chemoradiation (CRT) after curatively resected GBC. MATERIALS AND METHODS: We retrospectively analyzed the cohort of patients diagnosed between January 1999 and December 2009, treated with adjuvant CRT at our institution. Treatment protocol considered external beam radiation (RT) (45-54 Gy) to tumor bed and regional lymph nodes with or without concurrent 5-fluorouracil (5-FU) (500 mg/m2/day by 120-hours continuous infusion on days 1-5 and 29-33). Data was obtained from medical records, mortality from death certificates. Survival was estimated by Kaplan- Meier curves. RESULTS: 46 patients with curatively resected GBC received adjuvant CRT. Median age was 57 years (range 33-76); 39 patients were female. After diagnosis, a second surgery was performed in 42 patients. Cholecystectomy with hepatic segmentectomy and lymphadenectomy was the curative surgery in 41 patients. All patients received RT with a planned dose of 45 Gy in 25 fractions, 11 patients received a boost to the tumor bed up to 54 Gy and 34 patients had concurrent 5-FU. Therapy was well tolerated. Five patients experienced grade 3 toxicities. No grade 4 or 5 toxicity was observed. No grade >2 late toxicity was observed. Three- and 5-year overall survival (OS) were 57% and 51%, respectively. CONCLUSIONS: Adjuvant chemoradiation is well tolerated and might impact favorably on survival in patients with curatively resected GBC.

[Results of adjuvant chemoradiation after curative surgery for gastric cancer: a retrospective study]. / Quimiorradioterapia adyuvante en el cáncer gástrico resecado con intención curativa: Análisis de supervivencia y toxicidad de pacientes tratados entre 1995 y 2003 en el Instituto Nacional del Cáncer, Chile.

BACKGROUND: Survival rates after curative surgery for gastric cancer are disappointing. Therefore adjuvant therapeutic strategies are required. AIM: To analyze survival and side effects of treatment among gastric cancer patients treated with adjuvant chemo radiotherapy after curative resection of gastric adenocarcinoma. MATERIAL AND METHODS: Retrospective review of medical records of 74 patients aged 20 to 74 years, treated with complete resection of gastric adenocarcinoma followed by adjuvant chemo radiation. Survival analysis was based on the records and information from the National Mortality Registry. RESULTS: Five years survival fluctuated from 50% among patients in stage IB to 25% among those is stage IV. Significant acute toxicity was observed in 23 patients (31%). No patients died due to acute toxicity. Eleven patients (16.4%) developed significant late toxicity, with two possible deaths related to treatment. CONCLUSIONS: Postoperative chemo radiotherapy is feasible in our experience. Continues infusion of 5-fluoruracil is recommended to reduce toxicity.

Quimiorradioterapia adyuvante en el cáncer gástrico resecado con intención curativa: análisis de supervivencia y toxicidad de pacientes tratados entre 1995 y 2003 en el Instituto Nacional del Cáncer, Chile / Results of adjuvant chemoradiation after curative surgery for gastric cancer: a retrospective study

Background: Survival rates after curative surgery for gastric cancer are disappointing. Therefore adjuvant therapeutic strategies are required. Aim: To analyze survival and side effects of treatment among gastric cancer patients treated with adjuvant chemo radiotherapy after curative resection of gastric adenocarcinoma. Material and methods: Retrospective review of medical records of 74 patients aged 20 to 74 years, treated with complete resection of gastric adenocarcinoma followed by adjuvant chemo radiation. Survival analysis was based on the records and information from the National Mortality Registry. Results: Five years survival fluctuated from 50 percent among patients in stage IB to 25 percent among those is stage IV. Significant acute toxicity was observed in 23 patients (31 percent). No patients died due to acute toxicity. Eleven patients (16.4 percent) developed significant late toxicity, with two possible deaths related to treatment. Conclusions: Postoperative chemo radiotherapy is feasible in our experience. Continues infusion of 5-fluoruracil is recommended to reduce toxicity.

[Hodgkin lymphoma in Chile: experience of the national adult cancer program]. / Linfoma de Hodkin en Chile: experiencia de 15 años del Programa Nacional de Cáncer del Adulto.

BACKGROUND: Hodgkin lymphoma is a highly curable disease. AIM: To evaluate the clinical characteristics and the treatment results of Hodgkin lymphoma patients of the National Cancer Program in Chile. PATIENTS AND METHODS: Prospective assessment of 682 patients treated in 18 adult cancer centers. Progression free survival (PFS) and overall survival (OS) were calculated. Median follow up was 127, 95, 87, 72 and 50 months for C-MOPP, radiotherapy (RT), C-MOPP/ABV, NOVP and ABVD, respectively. RESULTS: Median age was 37 years (15-84). Nodular sclerosis and mixed cellularity were equally expressed. Advanced stages (III & IV) were present at diagnosis in 61% of cases. Age over 40 was an adverse prognostic factor (p<0.001). The rate of PFS at 5 and 10 years for early stages was 73% and 66% with RT, 80% and 74% with C-MOPP+RT, 73% and 71% with C-MOPP/ABV, 59% and 59% with NOVP+RT, and 81% with ABVD+RT, at 5 years, being significantly lower for NOVP (p=0.02). The rate of OS at 5 and 10 years for advanced stages was 82% and 70% with RT, 82% and 76% with C-MOPP+RT, 82% and 80% with C-MOPP/ABV, 68% and 60% with NOVP, and 85% with ABVD at 5 years, also significantly lower for NOVP (p=0.04). For advanced stages, the rate of PFS at 5 and 10 years was 49% and 43% with C-MOPP, 69% and 62% with C-MOPP/ABVD or C-MOPP/ABV, and 71% at 5 years with ABVD, significantly lower for C-MOPP (p=0.01). The rate of OS at 5 and 10 years was 52% and 46% with C-MOPP, 70% and 63% with C-MOPP/ABVD or C-MOPP/ABV and 76% with ABVD at 5 years, significantly lower for C-MOPP (p=0.0002). CONCLUSIONS: Age over 40 years was an adverse prognostic factor. C-MOPP/ABVD, C-MOPP/ABV and ABVD had comparable results and reached a high tumor control and overall survival in both early and advanced stages.

A proteomic approach to iron and copper homeostasis in cyanobacteria.

Cyanobacteria, which are considered to be the chloroplast precursors, are significant contributors to global photosynthetic productivity. The ample variety of membrane and soluble proteins containing different metals (mainly, iron and copper) has made these organisms develop a complex homeostasis with different mechanisms and tight regulation processes to fulfil their metal requirements in a changing environment. Cell metabolism is so adapted as to synthesize alternative proteins depending on the relative metal availabilities. In particular, plastocyanin, a copper protein, and cytochrome c(6), a haem protein, can replace each other to play the same physiological role as electron carriers in photosynthesis and respiration, with the synthesis of one protein or another being regulated by copper concentration in the medium. The unicellular cyanobacterium Synechocystis sp. PCC 6803 has been widely used as a model system because of completion of its genome sequence and the ease of its genetic manipulation, with a lot of proteomic work being done. In this review article, we focus on the functional characterization of knockout Synechocystis mutants for plastocyanin and cytochrome c(6), and discuss the ongoing proteomic analyses performed at varying copper concentrations to investigate the cyanobacterial metal homeostasis and cell response to changing environmental conditions.

Osteosarcoma: protocolo de tratamiento con quimioterapía y cirugía conservadora / Osteosarcoma: treatment protocol with chemotherapy and conservative surgery

Se presentan los resultados de un protocolo prospectivo de tratamiento combinado de quimioterapia y cirugía conservadora para el osteosarcoma clásico en etapas I A a II B (Enneking). Se evaluaron 64 pacientes, 39 hombres y 25 mujeres, con edades en rango de 14-60 años. La mediana de seguimiento fue de 40 meses (mínimo 20 y máximo de 72). Todos los pacientes fueron tratados con: doxorrubicina, cisplatino, ifosfamida y mesna en tres ciclos preoperatorios y ciclos postoperatorios, realizándose cirugía conservadora de reemplazos protésicos, alo o autoinjertos. La sobrevida actuarial fue de 60,2 por ciento a los 72 meses de observación. Se describe la relación del diagnóstico tardío con la incidencia de metástasis y sobrevida. Se enfatiza el buen resultado funcional y se recomienda el uso del protocolo presentado